WASHINGTON — The Pentagon is prepared to implement a new policy clearing the way for transgender men and women to join the armed forces, Military Times has learned, but final approval rests with Defense Secretary Jim Mattis, who could endorse, revise, delay or even abandon it.

Mattis faces a July 1 deadline, according to the parameters defined by his predecessor as defense secretary, Ash Carter. But the sensitive matter has become much more urgent for two transgender students now within days of graduating from the Army and Air Force military academies.

As USA Today first reported May 10, the unidentified cadets were recently informed that, absent a policy formalizing new accession standards, they won't be commissioned as military officers with the rest of their graduating class. Those proposed guidelines were sent to the defense secretary's office but Mattis has yet to act on them, according to multiple sources familiar with discussions surrounding the policy's implementation.

Meanwhile, neither the Army nor the Air Force has granted waivers to the cadets so they may proceed to serve in the active-duty military, causing some to question whether Mattis might decide against the proposed policy. Already, the Trump administration has moved to scale back federal protections for transgender students attending public schools, sending a strong signal it opposes further expanding such rights.

The Air Force Academy holds its graduation May 24 in Colorado Springs. West Point's ceremony, at which Mattis is slated to provide the commencement address, will be held May 27 in New York.

The Defense Department is "reviewing the readiness of the services to implement the accession of transgender personnel," Army Lt. Col. Myles Caggins, a Pentagon spokesman, told Military Times. He did not elaborate except to say there have been no changes to the policy, enacted by Carter in June, allowing transgender personnel already serving to do so openly and seek related medical care.

This readiness review follows a related decision, quietly approved by the Pentagon's sometime after Mattis took over in January, concerning bathroom and locker room access for transgender students attending Defense Department schools. A directive, issued last year after an incident in Germany, granted full access to transgender students' preferred facilities with no questions asked. Now, school principals — in consultation with students, their parents and teachers — address such matters case by case, as they had done previously.

These developments have led some to question whether Mattis, a retired Marine Corps general, may repeal or simply choose not to enforce this and other social policies adopted during the Obama administration that aim to streamline military recruiting practices by providing equal opportunity for men and women, regardless of gender and sexual orientation.

Mattis is a "hard read," said Todd A. Weiler, who, under Obama and Carter, served as the assistant secretary of defense for manpower and reserve affairs. "We'll know a lot more very soon about how he intends to stake his ground — and not just his stance on the transgender issue, but about 'don't ask don't tell' and expanding opportunities for women."

Weiler, who authored the military-wide school bathroom directive, was referring to two other signature personnel policies pursued by Obama during his eight years as commander in chief: One ending the ban on military service by homosexuals and the other opening ground combat jobs to women.

Mattis has questioned those moves in the past, telling Military Times last year: "We have to be very careful that we do not undercut battlefield effectiveness with shortsighted social programs." But during his Senate confirmation hearing, the retired general indicated he had "no plan to oppose women serving in any aspect in our military" and that he "never cared much about two consenting adults and who they go to bed with."

The Defense Department estimates as many as 7,000 transgender troops serve in the active-duty force of 1.3 million. As Carter sought to define accommodations for them, he encountered significant internal resistance among the department's longtime civilian staff who believed the military's uniformed leadership did not support such a significant change, said a former Pentagon official who spoke to Military Times on the condition of anonymity.

At its most extreme, this individual said, there were calls to require transgender troops to wear bathing suits while using communal showers.

Perhaps the most controversial aspect of Carter's policy calls for the Defense Department, and thus American taxpayers, to provide transgender personnel with medical care, to include reassignment surgeries and hormone treatment. In his June address lifting the ban, Carter indicated the accession policy would "require an individual to have completed any medical treatment that their doctor has determined as necessary ... and to have been stable in their identified gender for 18 months, as certified by their doctor before they can enter the military."

But that policy was never put into practice, according to Army and Air Force officials who've said that the services are not accepting transgender troops.

Logan Downs is a transgender man preparing to enlist in the Army

Christine Downs enlisted in the U.S. military three years ago, but she was forced to withdraw after injuring her knees. Today, Downs is ready to try again — as a transgender man named Logan.

Sign up for our NEW Good News Report - All positive stories about the military.

Carter also ordered the department to field a transgender policy for current personnel, which was published Sept. 30 and followed by service-specific directives. Weiler, who left the Pentagon in January, said an official count conducted that month suggested there were approximately 100 transgender troops currently serving who intended to fully transition and pursue related medical care.

"It's a nonissue," he said. "The numbers weren't going to be that big. I thought they'd just let it go through quietly ... because the overall cost becomes so minimal."

Since becoming President Trump's defense secretary, Mattis has said repeatedly that he intends to focus on bolstering the military's size, strength and war-fighting capabilities while curtailing expenses. Recent estimates suggest the necessary medical procedures and hospitalization for someone to transition from one gender to another can cost between $125,000 and $150,000. Writing in the New England Journal of Medicine, the Palm Center's Aaron Belkin calculated those costs to be much lower within the military's health-care system, averaging around $30,000 per person.

When approved last June, Carter's policy called for implementation to take place within 12 months. In that time, comprehensive training was expected to occur — "from commanders, to medical personnel, to the operating forces and recruiters," according to his guidance. That appears to be complete now and awaiting Mattis's review, according to multiple Pentagon officials.

But until that's settled, there will be no resolution for the two cadets stuck in limbo. The Air Force has said it is encouraging the student to work for the service in a civilian capacity.

A West Point spokesman, Lt. Col. Christopher Kasker, was unsure whether its student would be allowed to commission when and if the final policy is signed.

"The bad part for these cadets is they were planning to be Army and Air Force officers. Now we don't want them," Weiler said. "We've messed up their lives."

Andrew deGrandpre is Military Times' senior editor and Pentagon bureau chief. On Twitter